HD404374 Datasheet, PDF (104/161 Pages) Renesas Technology Corp – Low-Voltage AS Microcomputers with On-Chip A/D Converter

HD404374/HD404384/HD404389/HD404082/HD404084 Series
A/D Converter (HD404374/HD404384/HD404389 Series)
The MCU has a built-in successive approximation type A/D converter using a resistance ladder method,
capable of digital conversion of four analog inputs with an 10-bit resolution. The A/D converter block
diagram is shown in figure 63.
The A/D converter comprises the following four registers.
• A/D mode register (AMR: $028)
• A/D start flag (ADSF: $020,2)
• A/D data register (ADRL: $029, ADRM: $02A, ADRU: $02B)
• Module standby register 2 (MSR2: $00E)
Note : With the HD404374, HD404384, and HD404389 Series emulator, write 1 to bit 0 (ADRL0) of A/D
data register-lower (ADRL). This bit need not be written in the mask ROM and ZTAT^TM versions
in these series, although writing 1 will have no effect.
Interrupt flag
(IFAD)
R70/AN0
R71/AN1
R72/AN2
R73/AN3
*AN4
*AN5
Encoder
3
A/D data
register
(ADRU, ADRM, ADRL)
+
COMP
–
A/D
control
logic
A/D mode
register
(AMR)
Conversion time control
AVCC
AVSS
Reference
voltage control
A/D
start flag
(ADSF)
Operating mode signal (set to 1 in
stop, watch, and subactive modes,
D/A
and during module standby)
Note: * Applies to HD404389 Series.
Figure 63 A/D Converter Block Diagram
Rev.5.00, Sep.11.2003, page 104 of 161